chinese herb - strengthens immune systems

http://en.wikipedia.org/wiki/Astragalus_propinquus

huáng qí (yellow leader) (simplified Chinese: 黄芪; traditional Chinese: 黃芪)

or běi qí (traditional Chinese: 北芪), huáng hua huáng qí (Chinese: 黄花黄耆)

A. propinquus is used in traditional Chinese medicine, where it is used to speed healing and treat diabetes.[4]  In western herbal medicine, Astragalus is primarily considered a tonic for enhancing metabolism and digestion and is consumed as a tea or soup made from the (usually dried) roots of the plant, often in combination with other medicinal herbs. It is also traditionally used to strengthen the immune system and in the healing of wounds [5]  and injuries.[6]  Extracts of A. propinquus are used in Australia as part of a commercially available pharmaceutical MC-S to stimulate production of peripheral blood lymphocytes.

A. propinquus has been asserted to be a tonic that can improve the functioning of the lungs, adrenal glands and the gastrointestinal tract, increase metabolism, sweating, promote healing and reduce fatigue.[7] A mix of Astragali Radix and Salviae Radix, has been used to treat patients with chronic fatigue.[8]

There is a report in the Journal of Ethnopharmacology that Astragalus membranaceus can show "immunomodulating and immunorestorative effects.",[9]The herbal extract supplementation in drinking water can induce an immune stimulation response in immunosuppressed chickens[10] It has been shown to increase the production of interferon and to activate immune cells such as macrophages.[3]

There is a report in the journal Rejuvenation Research titled A Natural Product Telomerase Activator As Part of a Health Maintenance Program which shows that an extract of Astragalus propinquus, called TA-65®, can activate Telomerase extending the lengths of the shortest Telomers which protect the terminal DNA at the ends of all chromosomes. Telomer loss is associated with errors in cell division and is thought to be the primary cause of aging.

The active constituents of the roots (Radix Astragali) include polysaccharides, triterpenoids (astragalosides) [11] as well as isoflavones (including calycosin and formononetin) along with their glycosides and malonates.[

Other Astragalus spp. are known to cause severe poisonings in livestock due to indolizidine alkaloids, aliphatic nitro compounds and accumulated selenium.[14]  None of these constituents have been detected in the medicinal species Astragalus membranaceus used in dietary supplements and TCM preparations.[15]